Nuria Ofelia Núñez

NaDy _0.44 Gd _0.56 (WO ₄ ) ₂ @PAA nanoparticles have been developed, which are non-toxic to cells and C. elegans , and show X-ray attenuation and relaxivity properties that are adequate for their use as a dual T ₁ – T ₂ MRI contrast agent and as a CT probe.

Natural zeolites can be used to obtain effective catalysts for heterogeneous photocatalytic reactions due to their low cost and favorable physicochemical properties for water treatment. In this work, a natural clinoptilolite is modified by incorporating iron (NZ–Fe) and copper (NZ–Cu) as compensation cations through ion exchange processes. Metals incorporation and structural stability are demonstrated through X‐ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. DR‐UV–Vis measurements are used to estimate the bandgap and predict the photocatalytic performance of both materials. Their effectiviness in heterogeneous photocatalytic systems is confirmed by evaluating the inactivation of E. coli as a model pathogen in water. The bacterial detection limit (initial ≈10 ⁶ CFU/mL) is reached using 1 gL ⁻¹ of both catalysts, 100 ppm of H ₂ O ₂ under visible light (410–710 nm) and near neutral pH in 2 h, with no post‐treatment regrowth observed. Experimental data are analyzed according to the Chick–Watson, Weibull, and Hom disinfection kinetic models. Although more hydroxyl radicals are generated (trapping tests) and less iron leachate is observed for NZ–Fe, good reusability is attained for three disinfection cycles when NZ–Cu is used. This makes copper‐exchanged clinoptilolite a suitable and low‐cost photocatalyst for water disinfection through heterogeneous photo‐Fenton‐type processes.

Metal–organic frameworks (MOFs) have recently been proposed as a plausible solution to the pressing issue of water scarcity and as a means of remediating contaminated water bodies. In light-assisted water treatment, they have so far only been exploited via the hydroxyl radical route, through Fenton-like processes. A new avenue is introduced here by the biomimetic conceptual design of MOF bearing hypervalent metal atoms for photocatalytic water treatment. We report a zeolitic imidazole framework (ZIF) material doped with iron (Fe-ZIF-7-III; UPO-4) synthesized via a novel mild treatment to stabilize photoactive hypervalent ferryl ions for the first time in a MOF for water treatment. The successful synthesis of the 2D material and the adequate incorporation of iron into the structure were demonstrated using X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). A simulation study analyzed the structure and stability of the Fe-ZIF-7-III material as well as the involvement of ferryl ions in the photo-Fenton-type process. Furthermore, the calculated band gap of this material shows its viability for use in photocatalysis using sunlight. This was confirmed by evaluating the photodegradation of caffeine, a model pollutant in water, without the assistance of hydroxyl radicals as indicated by a scavenger test. The recyclability test revealed that Fe-ZIF-7-III could be used continuously with effective catalytic activity, thus opening the door to the field of studying hypervalent metal MOFs not yet explored in water treatment.

Dredged material is a common environmental and economic issue worldwide. Tons of highly contaminated material, derived from cleaning the bottoms of bays and harbours, are stored until depuration. These volumes occupy huge extensions and require costly treatments. The Ria of Huelva (southwest Spain) receives additionally high metal contamination inputs from the Odiel and Tinto Rivers which are strongly affected by acid mine drainage (acid lixiviates with high metal content and sulphates). These two circumstances convert the port of Huelva into an acceptor/accumulator of contamination. The current study proposes an alternative active treatment of dredged material and mining residues using ASEC (Adiabatic Sonic Evaporation and Crystallization) technology to obtain distilled water and valuable solid conglomerates. Different samples were depurated and the efficiency of the technology was tested. The results show a complete recovery of the treated volumes with high-quality water (pH~7, EC < 56 µS/cm, complete removal of dissolved elements). Also, the characterization of the dried solids enable the calculation of approximate revenues from the valorization of some potentially exploitable elements (Rio Tinto: 4 M, Tharsis: 3.7 M, dredged material: 2.5 M USD/yr). The avoidance of residue discharge plus the aggregated value would promote a circular economy in sectors such as mining and dredging activities.

NaLn(WO ₄ ) ₂ (Ln = Dy or Ho) nanoparticles functionalized with polyacrylic acid exhibit excellent performance as bimodal contrast agents for high-field MRI and X-ray computed tomography bioimaging and show tumor targeting ability through the EPR effect.

We have synthesized Eu-doped NaBi(MoO₄)₂ nanoparticles functionalized with PAA whose properties make them excellent multimodal contrast agents for X-ray computed tomography and luminescent bioimaging, as illustrated using a C. Elegans animal model.

Uniform spherical lanthanide-doped NaY(MoO₄)₂ nanoparticles have been synthesized, which, under UV illumination, exhibit intense multicolor luminescence and a high ability for the photocatalytic degradation of rhodamine B.

Uniform Nd³⁺-doped LuVO₄ nanophosphors have been synthesized for the first time in literature by using a poliol-based method at 120 °C from Nd³⁺ and vanadate precursors. After optimizing the Nd doping level, these phosphors present intense luminescence in the near-infrared biological windows. The X-ray attenuation capacity of the optimum nanophosphor has been found to be higher than that of a commercial X-ray computed tomography contrast agent. After surface coating with polyacrylic acid, such nanoparticles present high colloidal stability in physiological pH medium and high cell viability. Because of these properties, the developed Nd³⁺-doped LuVO₄ nanoparticles have potential applications as a bimodal probe for NIR luminescent bioimaging and X-ray computed tomography.